About this tutorial
Software products that provide a high availability of resources are becoming commonplace in today's computing environments. As the complexity of managing logical disks and their data increases in cluster environments, understanding and deploying an effective backup strategy for complete data protection is a top priority.
Our goal is to introduce a methodology for backing up and restoring UNIX and Linux data that resides in a cluster environment. Basic concepts of clustering and how Tivoli Storage Manager can be deployed in the cluster environment are introduced, and practical examples are given on how to configure the Tivoli Storage Manager Backup-Archive client and backup schedules. The migration procedure for Tivoli Storage Manager Backup-Archive client configurations that currently use clusternode option in AIX, HACMP environments is also described. The procedures outlined here depend on features introduced in Tivoli Storage Manager version 5.4.0.
The term cluster can mean many things to many different vendors and users. It can mean "highly available," "high performance," "load balancing," "grid computing," or some combination thereof. There are currently several clustering products available for UNIX and Linux. Our intent is not to provide a backup solution for any specific clustering product, but to define those aspects of a clustering environment that need to exist in order for this backup methodology to work correctly.
The concept of cluster, in this paper, refers to a UNIX or a Linux environment which exhibits the following characteristics:
- Disks are shared between physical machines, either in an exclusive fashion (only one host has access to the logical disk at any one time) or in a concurrent fashion.
- Disks appear as local disks to the host and not as network resources. We suggest that the file systems be mounted locally to the system, not through a LAN-based file share protocol such as network file system (NFS).
- Mount points of local disks are identical on each physical host in the environment (if file system /group1_disk1 fails from NodeA to NodeB, it is mounted on NodeB as /group1_disk1).
If the cluster environment exhibits all of the above characteristics, the methodologies we outline are supported by version 5.4 and higher of Tivoli Storage Manager Backup-Archive client. If the cluster environment only exhibits a subset (or none) of the characteristics, the methodologies outlined are not applicable and are not supported by Tivoli Storage Manager.
It is assumed that the reader has a basic understanding of how the Tivoli Storage Manager product functions, and that they have a basic understanding of how their cluster software functions. This paper does not address any cluster software related activities such as the development of application start and stop scripts.